It's been a few days since Google has announced their new algorithm structural search engine change called Caffeine. The company has been sort of secretive with what this change does exactly, but according to Matt Cutts, it's more about restructuring Google's engine rather than updating the SERPs.

When we looked into Caffeine, it is noticeably faster than the old search engine, but there are also obvious changes to the rankings when compared to what they used to be. Google is currently accepting feedback for Caffeine, so now would be a good time to try it out and complain if you don't like what Caffeine gives you when you search the terms you look for all the time.

Google assures us that this has nothing to do with certain other search engines making changes and partnerships, but it could still heat things up a bit more, since Google hasn't really been fighting back against Yahoo and Bing until this point (they haven't really had a reason to). Releasing some improved stuff on their engine couldn't hurt things now that they have a more viable competitor.

Caffeine isn't technically released yet, so we could see more changes to it before it actually comes out, but don't expect any ground-breaking user interface changes, this change is all on the back end.

It's tough to develop any concrete opinions about Caffeine, since it's still subject to change, but from what we see so far, it should be okay. It's nothing huge, but that's what Wave is for.